Apparatus for retaining solid material in a radial flow reactor and method of making

ABSTRACT

An apparatus for use in radial flow reactors is presented. The apparatus includes a first partition and a second partition with support members coupled therebetween. The first partition include a first opening and a second opening to allow the passage of fluid therethrough. A baffle extends into a flow channel formed by adjacent support members to obstruct an upper or lower portion of the first opening to interrupt a portion of the fluid flow therethrough.

CROSS REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. Provisional Application No.61/662,095 which was filed on Jun. 20, 2012.

FIELD OF THE INVENTION

This invention relates to cross or radial-flow reactors or adsorberswhere a fluid flows across a bed of catalyst or adsorbent. Inparticular, this relates to the internal components of a reactor oradsorber for distribution flow of the fluid and for providing a devicefor preventing the flow of catalyst or adsorbent across the inlet oroutlet screens.

BACKGROUND OF THE INVENTION

A wide variety of processes use radial flow reactors to provide forcontact between a fluid and a solid. The solid usually comprises acatalytic material on which the fluid reacts to form a product. Theprocesses cover a range of processes, including hydrocarbon conversion,gas treatment, and adsorption for separation.

Radial flow reactors are constructed such that the reactor has anannular structure and that there are annular distribution and collectiondevices. The devices for distribution and collection typicallyincorporate some type of screened surface. The screened surface is forholding catalyst beds in place and for aiding in the distribution ofpressure over the surface of the reactor to facilitate radial flowthrough the reactor bed. The screen can be a mesh, either wire or othermaterial, or a punched plate. For either a fixed bed or moving bed, thescreen or mesh provides a barrier to prevent the loss of solid catalystparticles while allowing fluid to flow through the bed. In a moving bed,solid catalyst particles are added at the top and flow through theapparatus and are removed at the bottom, while passing through ascreened-in enclosure that permits the flow of fluid over the catalyst.In a fixed bed, the catalyst, or adsorbent, is loaded into a bed betweenscreens, or other retention devices, and the screens allow fluid to flowover the catalyst while holding the catalyst in place. The screen ispreferably constructed of a non-reactive material, but in reality thescreen often undergoes some reaction through corrosion and/or erosion,and over time problems arise from the corroded or eroded screen or mesh.

One type of screen is a profile wire screen, where a profile wire iswrapped around supports and set at a predetermined spacing for the wireas it is wrapped around the supports. The screen is then cut andflattened and then re-rolled or re-shaped. The screen is shown in U.S.Pat. No. 2,046,458 and U.S. Pat. No. 4,276,265. When flattened, thescreen includes the profile wires, which are typically orientedvertically with support rods attached thereto and extending across theprofile wires and orthogonally therefrom. The screen can be used as partof an inlet distribution device, or other device for containing acatalyst. One type of inlet distribution device is a reactor internalhaving a scallop shape and is described in U.S. Pat. No. 6,224,838 andU.S. Pat. No. 5,366,704. The scallop shape and design provides for gooddistribution of gas for the inlet of a radial flow reactor, but usesscreens or meshes to prevent the passage of solids. The scallop shape isconvenient because it allows for easy placement in a reactor withoutconcern regarding the curvature of the vessel wall. The screens ormeshes used to hold the catalyst particles within a bed are sized tohave apertures sufficiently small that the particles cannot passthrough.

In one common approach, profile wire screen(s) are formed into agenerally tubular or cylindrical shape extending vertically within thegenerally vertical annular reactor about a central axis thereof. Aperforated plate may be spaced from the profile wires and connected toopposite edges of the support rods on a fluid side of the screen withinthe reactor, while the profile wires are typically oriented on amaterial side. The plates are also formed or oriented to into a tubularor cylindrical shape within the reactor. Depending on the type ofreactor and where within the reactor the screens are positioned, platesmay be closer to the center or the outer walls of the reactor. Asmentioned, the plates often include punched or perforated plates havinga plurality of openings. The support rods are oriented above and belowthe openings and provide a channel for fluid to flow from the openingsin the plate to the openings or mesh in the profile wire screens toprovide good distribution of the fluid to the solid catalyst oradsorbent bed. In one design, the reactor includes a centerpipe thatincludes an inner annular plate and an outer annular profile wire screenas described. Fluid flows from an inlet through the centerpipe andpasses through the plate openings and out of the screen to contact thecatalyst.

It has recently been identified that the fluid flowing through the plateopenings and channels can cause jetting which, when contacting thescreen and the solid material on the opposite side of the screen, maycause vibration of the screen and/or solid material and acceleratecorrosion or erosion of the outer surface of the profile wire screen andpotentially damage the solid material. This can decrease the life of theequipment and catalyst or adsorbent within the reactor, increasing thecost of maintaining the reactor as well as down time required forchanging out internal components of the reactor.

The design of reactors to overcome these limitations can savesignificantly on downtime for repairs and on the loss of catalyst, whichis a significant portion of the cost of processing hydrocarbons.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a reactor configuration in accordance with variousaspects;

FIG. 2 illustrates a reactor configuration in accordance with variousother aspects;

FIG. 3 illustrates a perspective view of a screen for use within aradial flow reactor in accordance with various embodiments;

FIG. 4 illustrates a side cross sectional view of the screen of FIG. 2.

FIG. 5 illustrates a plate for use within a radial flow reactor inaccordance with various embodiments; and

FIG. 6 illustrates an alternative plate for use within a radial flowreactor in accordance with various embodiments.

DETAILED DESCRIPTION OF THE INVENTION

Radial flow reactors often produce harsh chemical environments andsevere operating conditions in terms of pressure and temperature whichcreates tremendous stresses on the screens in these types of reactors.Thermal cycles and the weight of the catalyst can cause buckling of thescreens. Stronger screens or devices for retaining catalyst are needed.

Radial flow reactors, and cross-flow systems in general, need screens tocontain the catalysts used in the reactors. While the presentdescription is provided in terms of a reactor system, the equipment andprocesses described herein are applicable to adsorbers, or otherequipment used in contacting fluids with solids.

Catalyst chamber internals grids are currently used in olefinproduction, for example, such as the dehydrogenation of propane topropylene or iso-butane to iso-butylene to support one or more adsorbentbeds within the chamber or to separate individual adsorbent beds. Thegrids currently used are typically manufactured using profile wireconstruction.

Turning to FIG. 1, a radial flow reactor 10 in accordance with oneaspect is illustrated that includes inner and outer annular partitionsfor supporting an annular bed of solid material therebetween. Thereactor 10 includes a reactor shell 20, one partition in the form of acenterpipe 30, an outer partition in the form of screened partition 40,and a solid particle, or catalyst, bed 50. The reactor 10 by one aspectis configured so that fluid enters the reactor 10 through an inlet 32 atthe bottom of the reactor and travels upwardly through the centerpipe 30in the direction indicated by arrow 11. As the fluid flows upwardly,portions of the fluid are directed radially through the centerpipe, intothe catalyst bed 50 where the fluid contacts the catalyst and reacts toform a product stream. The product stream flows radially outwardlythrough the outer screened partition 40 and into annular space 14between the screened partition 40 and the reactor shell 20. The productstream is collected in the annular space 14 and passes through a reactoroutlet 12. According to another aspect illustrated in FIG. 2, thereactor may be configured to have an opposite flow pattern such thatfluid enters through an inlet 13 and enters annular space 14 between thereactor shell 20 and the outer screened partition 40 and flows radiallyinwardly through the catalyst bed 50 where it contacts the catalyst andreacts to form a product stream. The product stream flows radiallyinwardly through the center pipe 30 where it is collected in thecenterpipe and exits through the outlet 32. Other configurations of thereactor 10 and flow are also possible and contemplated herein.

As currently practiced, where the reactor includes a radial outward flowconfiguration like that shown in FIG. 1, the centerpipe 30 includes anouter catalyst-side profile wire screen and an inner fluid-sideperforated plate. The outer partition may also include an innercatalyst-side profile wire screen and/or an outer fluid-side perforatedplate. Alternatively, where the reactor includes the radially inwardflow configuration of FIG. 2, the outer partition 40 includes an innercatalyst-side profile wire screen and an outer fluid-side perforatedplate. The centerpipe 30 may also include an outer catalyst-side profilewire screen and/or inner fluid-side perforated plate. In both of theseconfigurations, the profile wire screen is subject to may stresses and acorrosive environment, including jetting of the fluid thereagainst andvibration of one or both of the profile wire screen and the catalystagainst the other, which can result in corrosion and erosion of theprofile wire screen and damage to the catalyst.

The partitions 30 and 40 must perform the duty of preventing the passageof solid catalyst particles and allowing the passage of fluid, whileproviding structural strength to hold the catalyst against the pressureof the weight of the solid particles.

In accordance with one aspect, an apparatus for retaining a solidmaterial in the reactor 10 is illustrated in FIGS. 3-4. The apparatus100 includes a fluid-side partition 102 and a catalyst-side partition105. As used herein, “fluid side” refers to the side or portion that iscloser to the fluid within the reactor, such as closer to fluid flowingthrough centerpipe 30 or in the annular space 14, while “catalyst side”refers to a side or portion closer to the catalyst bed 50 or other solidmaterial bed within the reactor. As described herein the apparatus mayinclude or form a portion of the centerpipe 30 and/or the outerpartition 40. For ease of explanation, the following will be describedwith regard to an apparatus for use as part of a centerpipe 30 withinthe outwardly radial flow configuration reactor of FIG. 1, although itshould be understood that these principles and this description may beapplied to the other reactor designs discussed above. Explanation of areactor and components as having a cylindrical structure, is intended toinclude cylindrical structures, but also structures composed ofindividual planar components that when assembled make a multisidedstructure, such as having the cross sectional shape of an octagon ordodecagon, or any polygonal shaped cross-section, but can besubstantially treated as a cylindrical structure.

By one aspect the fluid-side partition 102 includes a plate 104 havingopenings 106 therethrough. When positioned in the reactor 10 the platehas an annular form about a center axis 17 of the reactor 10, and may beformed in different manners, including, for example, a single hollowcylindrical plate or tube or a plurality of flat or arcuate platespositioned circumferentially side-by-side about the axis 17. The platealso includes openings 106 extending through a thickness of the plate104. The openings 106 may be circular or other shapes, including avariety of polygonal shapes or slots extending about the plate. Asillustrated in FIG. 3, the plate includes round openings 106 that may bepunched or drilled through the plate 104.

According to an aspect, the catalyst-side partition 105 includes aprofile wire screen 108. U.S. Pat. Nos. 2,046,458 and 4,276,265, whichare incorporated by reference herein disclose typical structures andmethods of making profile wire screens. The profile wire screen 108includes a plurality of generally vertically oriented and horizontallyspaced profile wires 110 and a plurality of generally horizontallyoriented and vertically spaced support members 112 extending across theprofile wires 110. The support members 112 extend generally orthogonallyfrom the profile wires 110 and are coupled thereto at one end portion114 thereof. It should be understood that for ease of descriptionherein, terms such as horizontal and vertical are used to describe thepartitions 102 and 104 on a standalone basis as illustrated in FIG. 3.However, it should be understood that when the partitions are formed forbeing used in the reactor 10 or are positioned within the annularreactor 10, horizontal may refer to circumferential or radial, whilevertical may refer to axial. For example, when situated within areactor, the profile wires 110 will be generally axially oriented andcircumferentially spaced about the center axis 17 of the reactor 10.Similarly, the orthogonally extending support members 112 may extendradially inward or outward depending on the configuration of thereactor.

By one aspect, the support members 112 include support rods 114. Thesupport rods 114 may be coupled at an opposite edge portions 115 and 116between the profile wires 110 and the plate 104. The profile wires 110and support rods 114 form openings or slots 124 through the profile wirescreen 108 where they intersect. By one aspect, the edge portions 116 ofadjacent support members are vertically aligned above and below theopenings 106 of the plate 104. In this manner an upper surface 118 of alower support member and a lower surface 120 of an adjacent uppersupport member form a fluid channel 122 in fluid communication with theplate opening 106 and the slot 124. In this manner a plurality of fluidflow channels 122 are formed vertically along the apparatus 100 todefine fluid flow paths for the flow of fluid through the apparatus orpartition 100, for example centerpipe 30.

By one aspect, a baffle 126 extends into the fluid flow path to obstructor interrupt at least a portion of the flow of fluid therethrough. Inone example, the baffle 126 extends into one of an upper portion 128 ora lower portion 130 of the fluid flow path or channel 12 that is distalfrom the inlet 32 of the reactor 10. That is, for example where theinlet 32 is at a bottom portion of the reactor as illustrated in FIG. 1,the baffle extends into upper portion of the opening 106 or channel 12.In another example, the baffle 126 extends into one of the upper portion128 or lower portion 130 of the fluid flow path or channel that isdistal from the direction from where the fluid is flowing flows. Thatis, with regard to FIG. 3, where the fluid travels vertically upwardalong the plate 104, the baffle 126 extends into an upper portion 128 ofthe fluid flow path or channel 122 to obstruct an upper portion of thechannel 122 and/or opening 106 as illustrated in FIG. 3. On the otherhand, where the fluid travels vertically downward along the plate 104,the baffle 126 extends into a lower portion 130 of the fluid flow pathor channel 122 to obstruct a lower portion of the channel 122 and/oropening 106. Surprisingly, it has been identified that by positioning abaffle within the flow channel in this manner, fluid jetting can bereduced and a more even fluid velocity profile within the channel 122and along the profile wires 108 can be achieved to reduce localized peakvelocities that cause vibration and erosion and corrosion of the profilewires screen 108 and/or the catalyst.

Where this description describes the baffle obstructing an upper orlower portion of an opening or channel, this includes the baffleobstructing the opening alone or in combination with another component,such as the support rod 114. For example, as illustrated in FIG. 4, thesupport rod 114 and baffle 126 both partially obstruct the opening 106.

By one example, the baffle extends into to flow path to obstruct betweenabout an upper 5 and 70% of the opening 106 and/or channel 122. Byanother example, the baffle 126 extends into the flow path to obstructbetween about an upper 10 and 50% of the opening 106 and/or channel 122.By yet another example, the baffle 126 extends into the flow path toobstruct between about an upper 20 and 30% of the opening 106 and/orchannel 122. In these examples the baffle may obstruct between about 75and about 100% of the width of the openings in one example and betweenabout 85 and about 100% of the width of the openings in another example.

By one example, the opening has an opening height between about 10 andabout 25 mm. In another example the opening has an opening height ofbetween about 11 and about 21 mm. In yet another example, the openinghas a height of between about 11 and about 13 mm. In one example, thebaffle obstructs between about an upper or lower 2 and 10 mm of theopening height. In another example the baffle obstructs about an upperor lower 3 and 7 mm of the opening height. In one example, the supportrod 114 has a thickness of between about 2 and about 10 mm and thebaffle extends vertically from the support rod by between about 1 andabout 5 mm and in another example from between about 2 and about 4 mm.

By one aspect, as illustrated in FIGS. 3 and 4, the baffle 126 iscoupled to the support member and extends vertically therefrom into oneof the upper and lower portions of the fluid flow channel 122. In theillustrated example, the baffle 126 extends down from an end portion 116of the support rod 112, generally adjacent to the plate 106. In anotherexample the baffle may extend into the opening 106 itself. In yetanother example the baffle extends down from the support member 114 at adistance away from the plate 104 and between the plate 104 and profilewires 110. By one example, a front face 130 of the baffle 126 ispositioned between being adjacent to the plate 104 to being about 50% ofthe distance between the plate 104 and the profile wires 110. By anotherexample, a front face 130 of the baffle 126 is positioned between beingadjacent to the plate 104 to being about 30% of the distance between theplate and the profile wires 110. In one example, the front face 130 ofthe baffle 126 is positioned between about 10 and about 50% of adistance between a fluid-side face 132 of the plate and the profilewires 110. By another example, the front face 130 of the baffle ispositioned between about 20 and about 35% and in another example betweenabout 25 and about 30% of a distance between a fluid-side face 132 ofthe plate and the profile wires 110. In another example a baffle offsetdistance (distance between the fluid-side face 132 of the plate and thefront face 130 of the baffle) to opening height ratio is between about0.5 and about 1.5 and in another example is between about 0.75 andabout 1. Surprisingly, it has been found that having the baffle frontface 130 offset from the fluid-side face 132 of the plate improves theflow characteristics, decreases localized peak velocities, and reducescorrosion and erosion versus having the baffle aligned with or veryclose to the front face of the plate or simply decreasing the size ofopenings 106 in the plate.

By one aspect the baffle is coupled to support rods 112 and extendstherefrom. The baffle 126 may extend generally orthogonally from thesupport rods 112. According to one aspect, as illustrated in FIGS. 3-4,the support rods 112 have an L-shaped cross section with one leg of thesupport rod 112 extending generally orthogonally from the profile wirescreen to form a main portion 134 of the support rod and the other legof the support rod providing the baffle 126 that extends down from thesupport rod 114. In this manner, the baffle 126 may be generallyadjacent to the plate 104. According to another aspect, as illustratedin FIG. 5, the support rod 112 may have a T-shaped cross section havinga main portion 150 for coupling to and extending orthogonally from theprofile wires 110 and a baffle portion 152 extending from the mainportion 150 and generally parallel to the profile wires 110 to providethe baffle 126. In this manner, the baffle 126 may be offset from theplate 104. According to either of the aspects discussed above, thesupport rod 114 may be formed in any known manner, including welding orbending of the rod to form the L-shape or T-shape thereof.

By another aspect, as illustrated in FIG. 6, the baffle 200 is integralwith a plate 202 itself. The baffle 200 may be provided alternatively toor in addition to another baffle extending from the support rod 114. Inthis manner the baffle 200 extends partially into the opening 204.According to this aspect, the plate includes a first partial opening 206that extends from a fluid-side face of the plate through a portion of athickness of the plate 202. The plate includes a second partial opening208 that extends through another portion of the thickness of the plateto an opposite face of the plate. The first and second openingsintersect to form the opening 204 extending through the entire thicknessof the plate 202. An upper surface or edge portion 210 of the secondpartial opening 208 is vertically offset below an upper surface or edgeportion 212 of the first partial opening 206. In this manner, a portionof the plate material above the second opening edge portion 210 providesthe baffle 200 for obstructing or interrupting at least a portion of theflow of fluid therethrough. According to another aspect, the plate 202may include two partial plates that are joined together such as bylaminating. The partial openings 206 and 208 may be openings through thepartial plates and the plate may be formed by aligning the plates sothat the upper edge portion 210 of the second partial opening of thesecond partial plate is below the first partial opening 206 upper edgeportion 212 of the first partial plate. In this manner, the baffle 200includes the material of the second partial plate above the secondpartial opening upper edge portion 210. It should be understood thatwhere it is desired to obstruct a lower portion of the opening 204 orflow channel 122, an opposite configuration is also contemplated hereinso that baffle 200 is at a bottom portion of the opening 204.

In accordance with one aspect, a method is provided for forming anapparatus for retaining solid particles in a reactor. The methodincludes providing a profile wire screen having a plurality of generallyparallel spaced wires supported by a plurality of generally parallelelongate support rods coupled at one edge portion thereof to the profilewires. The support rods may extend generally orthogonally from theprofile wires to define openings where the profile wires and supportrods intersect. The method further includes forming baffles coupled toand extending from the support rods. The method also includes providinga plate having a plurality of openings. The openings may be formed, forexample, by drilling, milling, or punching the plate.

The method according to an aspect includes arranging the support rods toextend between the profile wires and the plate, with the plate generallyparallel to the support wires to that adjacent support rods define aflow channel in fluid communication with a plate opening and a profilewire screen opening. In this manner, an upper support rod defines anupper surface of the flow channel and an adjacent lower support roddefines a lower surface of the flow channel. The method further includespositioning at least a portion of the baffle to obstruct one of an upperand lower portion of the flow channel so that fluid flowing therethroughwill be at least partially obstructed by the baffle portion. The methodalso includes connecting the support rods between the profile wires andthe plate to form the partition or apparatus. Forming the baffles,according to an aspect, includes bending an edge portion of the supportrods downward to form a generally L-shaped cross section of the supportrods with the baffle including one leg of the L-shaped cross section. Onthe other hand, other methods can be used to form a baffle extendingfrom the support rod, including, but not limited to attaching a baffleto the support rod through welding or other means, and the baffle may beformed intermediate edge portions of the support rod, to provide asupport rod with a generally T-shaped cross section.

By one aspect the baffle may be formed to extend down from the supportrod and aligned to obstruct an upper portion of the plate opening whencoupled thereto.

According to another aspect, a method of forming an apparatus orpartition as generally described herein includes arranging a pluralityof elongate support rods having one of a T-shaped and L-shaped crosssection generally parallel to one another to define vertices of animaginary polygon. The method may include aligning the support rods sothat one portion or leg thereof extends generally radially inwardly withregard to a profile wire screen cylinder that will be formed, and theother leg of the L-shaped support rod or the bottom of the T-shapedsupport rod extends generally tangential to the cylinder. The methodincludes helically winding a profile wire about the support rods downthe lengths thereof along an edge portion of the support rods. Each coilis spaced from adjacent coils and joined to the support rods. In thismanner a generally cylindrical profile wire screen is formed. The methodfurther includes cutting the profile wire between two of the supportrods and generally parallel thereto and opening the profile wire screen.The profile wire screen may be flattened and positioned so that theprofile wires extend generally vertically and the other leg of theL-shaped support rod or a bottom portion of the T-shaped support rodextends generally parallel to the profile wires to form a baffle.

According to this aspect, the method may also include providing a plateas described above having a plurality of openings extendingtherethrough. The method also includes arranging the profile wire screenand the plate so that the baffles vertically away from the support rodto partially block an upper or lower portion of the opening. The formedpartition may then be formed into a generally cylindrical shape to bepositioned within a reactor. For example, a plurality of such partitionsmay be formed and positioned side-by-side in an arcuate arrangement orone or more partitions may be curved to form the generally cylindricalpartition.

According to yet another aspect, a method of making a partition forretaining a solid in a radial flow reactor includes providing a platehaving a thickness and forming a partial opening on one side of theplate through a first portion of the plate thickness. The formed firstopening includes an upper edge portion or surface at a first verticalheight. The method includes forming a second partial opening on anopposite side of the plate through a second portion of the platethickness having a second upper surface below the first upper surface sothat the first and second openings intersect to form a complete openingthrough which fluid may flow. The portion of the plate above the secondupper surface forms a baffle to obstruct an upper portion of the firstopening. Alternatively the above method could be carried out, however toform the baffle at a lower portion of the first opening, as should bereadily understood. By one aspect, the method includes forming the firstand second partial openings by removing plate material from one side ofthe plate through the first portion of the thickness thereof andremoving plate material from the other side of the plate through thesecond portion of the thickness. In another aspect, the second openingis formed by forming a smaller opening through the second portion of theplate material by removing material through the first opening. By yetanother aspect, first and second partial openings may be formed in aplurality of partial plates and the partial plates can be aligned toform the baffle and joined together, such as through laminating thepartial plates together.

While this description has been provided with regard to specificembodiments, it is to be understood that this description should not belimiting to the disclosed embodiments, but it is intended to covervarious modifications and equivalent arrangements included within thescope of the appended claims.

The invention claimed is:
 1. An apparatus for retaining a solid in areactor comprising: a generally vertical fluid side partition having afluid side opening to allow passage of the fluid therethrough; agenerally vertical solid side partition spaced radially from the fluidside partition and generally parallel thereto having a solid sideopening to allow passage of fluid therethrough; a fluid flowpath betweenthe fluid side opening and the solid side opening; and a baffleextending into the fluid flowpath to obstruct an upper portion of thefluid side opening and partially interrupt the flow of fluid along thefluid flowpath.
 2. The apparatus of claim 1, further comprising a firstsupport member coupled between the fluid side partition and the solidside partition with an end portion positioned generally above the fluidside opening and a second support member coupled between the fluid sidepartition and the solid side partition with an end portion positionedgenerally below the fluid side opening to define a fluid flow channeltherebetween in fluid communication with the fluid side and solid sideopenings and wherein the baffle depends from the first support memberinto an upper portion of the fluid flow channel to interrupt the flow offluid therethrough.
 3. The apparatus of claim 2, wherein the baffle isattached to the first support member.
 4. The apparatus of claim 2,wherein the first support member is an L-shaped support rod and thebaffle comprises one leg of the L-shaped support rod.
 5. The apparatusof claim 1, wherein the baffle extends downward to obstruct betweenabout an upper 5% and an upper 70% of the fluid side opening.
 6. Theapparatus of claim 1, wherein the baffle is positioned between aboutbeing adjacent to the fluid side partition to about half way between thefluid side partition and the solid side partition.
 7. The apparatus ofclaim 1, wherein the fluid side opening has a height of between about 10and about 25 mm and the baffle obstructs between about 2 and about 10 mmof the upper portion of the fluid side opening.
 8. The apparatus ofclaim 1, wherein the solid side partition comprises a profile wirescreen and the fluid side partition comprises a perforated plate.
 9. Theapparatus of claim 1, wherein the fluid side partition comprises a platehaving a thickness and the fluid side opening includes a first partialopening on one side of the plate extending partially through thethickness of the plate with an upper first opening edge portion at afirst height and a second partial opening on an opposite side of theplate intersecting the first partial opening to provide the fluid sideopening extending through the entire plate thickness and having an uppersecond opening edge portion at a second lower height than the firstheight so that the baffle includes the upper second opening edgeportion.
 10. An apparatus for retaining a solid in a reactor comprising:a profile wire screen including a plurality of generally verticallyaligned and horizontally spaced profile wires and first and secondvertically spaced support rods extending generally horizontallythereacross and coupled at one edge portion to and extendingorthogonally from the plurality of profile wires to define a screenopening through the profile wire screen; a plate spaced from theplurality of profile wires and coupled to an opposite edge portions ofthe first and second support rods; a plate opening of the plategenerally below the first support rod edge portion and above the secondsupport rod edge portion; a lower surface of the first support rod andan upper surface of the second support rod defining a fluid flow channelin fluid communication with the plate opening and the screen opening toallow fluid to flow therethrough; and a baffle extending downward intothe fluid flow channel to obstruct an upper portion of the plate openingto partially interrupt the flow of fluid therethrough.
 11. A radial flowreactor for contacting a fluid with a solid material comprising: acenterpipe for receiving fluid flowing in a fluid flow direction; aninlet in communication with the centerpipe for providing the fluidthereto; an annular bed of solid material surrounding the centerpipe forcontacting the fluid; a permeable annular partition surrounding the bedof solid particles for supporting the bed of solid material; a reactorwall spaced from and surrounding the annular partition to define a fluidexit space therebetween; an outlet in fluid communication with the fluidexit space for removal of fluid from the fluid exit space; an outerprofile wire screen of the centerpipe with a plurality of generallyvertically aligned and circumferentially spaced profile wires forrestricting the solid material from entering the centerpipe; first andsecond vertically spaced support rods of the profile wire screenextending generally circumferentially across the profile wires andcoupled at one edge portion thereof to the profile wire screen andextending radially inwardly therefrom; an annular plate of thecenterpipe having a plate opening generally below the first support rodand above the second support rod with an outer surface thereof coupledto an opposite edge portion of the first and second support rods; alower surface of the first support rod and an upper surface of thesecond support rod defining a fluid flow channel in fluid communicationwith the plate opening and the screen opening to allow fluid from thecenterpipe to flow therethrough and into the bed of solid material; anda baffle extending into the fluid flow channel to obstruct one of anupper and lower portion of the plate opening that is opposite the fluidinlet.